Treating hydrocarbon oils



Aug. 30, 1932. o. BEHIMER 1,874,860

TREATING HYDROCARBON oILs original Filed May 18, 1927 2 sheets-sheet 1FHAcT/oNAT/NG coL uM/v nEcE/v//ve @RUM Aug- 30, m32. B-EHIMER TREATINGHYDROCARBON OILS original Filed May 18, v1927 2 Smets-sheet @theme43.AWM

Patented Aug. 30, l1932 UNITED vSTATES PATENT oFFIcE OTTO BEHIMER, OFCHICAGO, ILLINOIS, ASSIGNOR TO THE TEXAS COMPANY, OF NEW YORK, N. Y., ACORPORATION OF DELAWARE TBEATING HYDROCARIBON OILS Application led May18, 1927, Serial No. 192,226. Renewed October 3, 1929.

This invention relates essentially to certain novel methods offractionating hydrocarbon oils and has special `reference to certainmethods of treating the evolved vapors and distillates of pressurecracking stills.

My invention contemplates carrying on the dephlegmation andfractionation of the evolved vapors, and handling the condensates, insuch a way as to obtain the well known advantages of fractionating andcondensing under` pressure and at the same time produce a properlyfractionated or stabilized gasoline or naphtha distillate. At thepresent timey gasoline specifications call for a 96% recovery asindicated on the Standard Engler distillation flask whereas in thegasoline distillate ,usually taken od' pressure cracking systems thepercent recovery is considerably lower, for example about 92%. Myinvention enables the production of a suitably fractionated or rectifieddistillate and with a minimum of loss of liquid components in the'cxitgases from the system.

My invention contemplates the use of heat contained in products derivedfrom the cracking re-action to supply the heat necessary to fractionateor rectify the distillate and the practice of my invention a portion of.the vapors is withdrawn and conducted to the rectifying or fractionatingapparatus, thereby supplying the heat necessary for removing the fixedgases from the distillate. In one way of carrying on my invention thevapors from the cracking still are subjected to a primary'separation asby condensation, or preferably fractionation, to form a liquidcomprising the heavier constituents which it is undesirable to have inthe final distillate and a lighter vapor fraction comprising essentiallythe hydrocarbons desired in the final gasoline or naphtha distillatetogether with fixed gases; a portion of the vapor fraction is conductedto a condenser and the liquid condensate is drawn od and rectied orfraction-` ated, the heat required being supplied by the other portionof the vapor fraction.

paratus shown in Figure 1, 10 designates the primary separator orfractionating column, 11 the condenser for condensing the vapor fractionfrom the fractionating column and l2 the fractionating column employedin treating the final condensate. The vapor product to Jbe treated isintroduced to the 35 separator 10 through a vapor line 13 which is incommunication with a pressure cracking still not shown. The separator 10is of any suitable form but is preferably a fractionating or rectifyingcolumn containing suitable contact material or apparatustov facilitatecontact of the down dowing liquid and upl wardly rising vapors therein.The column may well be in the form of a bubble tower.

It is shown equipped with a redux condenser 14 interconnected with avapor line 15 and a redux condensate line 16. A vapor l-ine 17 providedwith a valve 18 extends from the fractionating apparatus, or morespecifically `from the redux condenser 14, to a condenser 30 column 10.

A line 20 having a valve 21 serves to conduct the condensate from thecoil 11 to a re- 85 ceiving drum 22 which is equipped with a valved gasoutlet line 23 and a valved condensate outlet line 24. The line 24 isshown as terminating in a midpoint in the fractionating or rectifyingcolumn 12.' This 90 column is shown equipped with a redux condenser 25with an interconnecting gas line 26 and redux condensate line 27. Theredux condenser 25 as well as the redux condenserl 14 are supplied withcooling from any suit-l 95 able source and it is to be understood thatthe redux condensers constitute parts of, or are adjuncts to, theirrespective fractionating columns and that if desired other cooling meansmay be supplied, such for example as 19 lfrom the vapor line 17 to acoil 30 in the lower part of the fractionating column 12.

This coil is connected by a pipe 31 to a coil l32 mounted in suitablecooling apparatus 33,

and a pipe 34 connects the coil 32 with the receiving drum 22. Thefractionating or rectifying column 12 may be provided with any suitablecontact apparatus or material.

An advantageousarrangement is to have A.tanks not shown bubble trays inthat portion. of the tower above the point in which the ipe 24 entersand merely baies or plates int e portion below the point of entry yandabove the coil 30. A valved pipe 35 is provided for conducting therectified or fractionated distillate to treating apparatus for purifyingor rendering it stable from the chemical standpoint, or the ipe 35-maextend to suitable storage In practicing the inventionillustrated inFigure y1, the vapors from the pressure still,

are conducted to the rectifying or fractionatling column 10 andsubjected to rectication therein to' form a vapor fraction which isremoved through thefline 15, reiux condenser 14' and vapor line 17. Theliquid fraction is preferably returned to the cracking zone forregt'reatment. The valve 18 is normally l f open and the vapors passwithout obstruc- A' tion 't'o the condenser 11 except such vportions ivalve 29 being opened sufficiently to permit l asaredrawn off throughthe line 28, the

thehiwithdrawal of the desired portion of vapors and their admission tothe coil 30. The primary separation 'or fractionation carried on in thecolumn'lO is preferably con- ',ductd under amaterial superatmospheric ppressure and may Well be under approxi-y valve 21Amay be used as apressure reducingmately .thesame pressure as that of the cracklng stilllfrom which the vapors to be treated are Withdrawn. While the valve 18may be used as apressure reducing valve to reduce the ressure inthecondenser 11, it is general y preferable tjo maintain the high pressurethrough the condenser 11. The conden-- sate formed in f the condensatecoil 11 together with the contained gases passes through the pipe' 20lnto the receiving drum 22. The

valve to reduce the pressure to a greater or lesser extent Jin thereceiving drfum 22. The condensate. collected in the receiver is f edthrough the line 24 into the fractionating column 12. The valve intheline 24 may serve as a means for dropping the pressure a further amountin the fractionating colf umn. The condensate thus introduced thefractionating column is subjected therein to fractionation orrectification and the heating coil 3() serves to heat the final orultimate condensate formed inthe column and insure that practically allof the'gaseousconf lstituents are removed therefrom. While therectifying operation carried on in the column pressure obtaining in thecondenser 11 or the ,fractionating column 10, such a procedure is not tobe recommended in view of the diiiiculty encountered in thoroughlyremoving the xed' gases from the liquid condensate at higher pressures.It is therefore desirable `to carry on the rectifying of the`*distillate in the column 12 at a pressure materially reduced from thatobtaining in either the frac- 'tionating column 10 or the condenser 11and in fact it is generally' preferable to maintain the column 1 2 underpressures approaching atmospheric. However, it is generally detifcation,as in apparatus 55, the 'pressure in the column may be advantageouslyused to force the distillate through the treating vessels. In caseswhere the cracking operation is carried on under several hundred pounds12 may be conducted at substantially the s sirable to maintain somevpressure above atpressure, for example, and a similar pressure ismaintained in the fractionating-column l 10 and condenserll, the column12-may be conveniently held under pressures ranging from about 25 to 50pounds.

The vapors and gases in the coil 30 togethj `er with condensate formedtherein are con-4 ductedby the pipe 31 to the cooling coil 32 and passedthence through the line 34 into the receiving drum 22. In some cases thecooling coil 32 may be dispensed with but ordinaril there will not besufficient cooling, by the eat exchange between the coil 30 and th'eliquid in the bottom ofthe fractionating column 12, to condense all thecondensable constituents passing through the coil 3 0 andit is generallydesirable to further cool the uids discharged from the coil 30 so thatsubstantially `all the condensable Afractions may be liquified. It is ofcourse desirable 'to have the gases passing out through'the line 23 andalso the gases leaving'through the ipe 36 in as dry a condition aspossiblef Orinarily the gases leaving through the pipe 23 willcontain'some condensable fractions column 12, the gases removed fromthe'line 36 may be substantially dry.

` but if ,adequate cooling be supplied to the I In the apparatus shownin Figure 2, the

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any condensate formed in the coil 38. VThe tower is shown equipped witha reflux condenser 40 with an interconnecting vapor line 4l and refiuxcondensate line 42. The gases are Withdrawn through a pipe 43 and therectified liquid is removed through a line 44. This particular type ofequipment is Well adapted foroperations in which it is desired to carryon the fractionation in the column 374 under material superatmosphericpressures and this system is furthermore Well adapted for operations inwhich the liquid condensate drawn off through pipe 44 is forced throughtreating apparatus containing treating materials for purifying andstabilizing the distillate.

In the apparatus illustrated in Figure 3, the outlet pipe 20 extends toa receiving drum or chamber 45 andthe pipe 28 is in communication with aperforated pipe or coil 46 positioned in the bottom of the drum 45 sothat the hot vapors and gases withdrawn from the pipe 17 may beintroduced directly into the distillate to be stripped or fractionated.The vapors evolved in the receiving drum are Ifractionated or rectifiedin a column 47 which is connected to the drum by means of a vapor line48 anda refiux condensate line 49. The rectifying column 47 is shownequipped with a refiux condenser 5() with an interconnecting vapor line51 and a reflux condensa-te line 52. The gases are Withdrawn through apipe 53 and the rectified condensate is drawn ofi' from the rect-ifyingapparatus through a line 54. The method of operationillustrated inFigure 3 has the advantage of) efficient heatl exchange of the hotvapors by direct contact with the liquid to be rectified and also makespossible the utilization ,of the vapors and gases introduced through theline 28 to act as a carrier for removing the fixed gases from theliquid. This methodhas, however, a disadvantage as compared with themethods shown in Figures 1 and 2 since when the vapors and gasesintroduced through'line 28 are thus admitted into direct contact withthe v liquid being rectified, there may be oppor-v tunity for someentrainment or absorption of gas in the liquid collected in thereceiving drum. However, this tendency toward gas absorption isminimized by reason of the heated condition of the gases introduced.

Abviously many modifications and variations of the invention, ashereinbefore set forth, may be made Without departing from the spiritand scope thereof, and therefore only such limitations should be imposedas are indicated in the appended claims.

What I claim is:

l. In the treatment of hydrocarbon oils, the process that comprisesremoving vapors from ay pressurerstill and While still maintaining themunder pressure, effecting a primary separation thereof into a liquid anda. vapor fraction, subjecting a portion of the vapor fraction to coolingto form a condensate, subjecting this condensate to rectification toform a rectified liquid While'passing the other portion of said vaporfraction into heat exchange with the ultimate condensate 'of therectification. v

2. In the treatment of hydrocarbon oils, the `process that comprisesremoving vapors from a pressure still and While still maintaining themunder pressure, effecting a primary separation thereof into a liquid anda vapor fraction, subjecting a portion of the vapor fraction to coolingto form a condensate, subjecting this condensate to rectification underreduced pressure to form a substantially dry gas and a rectified liquidWhile passing the other portion of said vapor fraction into heatexchange relation with the ult-imate condensate of the rectification.

3. In the treatment of hydrocarbon oils,

the process that comprises removing vapors from a pressure still andWhile still maintaining them under pressure, effecting a primaryseparation thereof into a liquid and a vapor fraction, subjecting aportion of the vapor fraction while still under pressure to cooling toforni a condensate, reducing the pressure on the condensate, subjectingthis condensate to rectification under the reduced pressure to form arectified liquid while passing the other portion of said vapor fractioninto heat exchange relation with the ultimate condensate of therectification.

4. In the treatment of hydrocarbon oils, the process that comprisesconducting vapors from a pressure still to a rectifying column andsubjecting the vapors to rectification therein 'While still under amaterial superatmospheric pressure, removing evolved vapors from therectifying column and subjecting a portion of them to cooling to form acondensate, introducing the condensate to a rectifying column andsubjecting the condensate to rectification therein to form asubstantially dry gas and an ultimate condensate While passing the otherportion of the vapors from the rst rectifying column in heat exchangerelation with the ultimate condensate of the second rectifying column.

5. In the treatment of' hydrocarbon oils, the process that comprisesconducting vapors from a pressure still to a .rectifying column andsubjecting the vapors to rectification therein while still under amaterial supersecond rectifying column and subjecting the condensate torectification therein to form a substantially ,dry gas and an ultimatecondensate while passin the other portion of the vapors from the rstrectifying `column through a conduit in heat exchange with said ultimatecondensate of the second rectifying column.

6. In the treatment of -hydrocarbon oils, 1Q the process that comprisesconducting vapors from a pressure still to a rectifying column Aandsubjecting the vapors to rectification therein while still under amaterial superatmospheric pressure, removing evolved vapors from therectifying lcolumn and subjecting a portion of them lto cooling toiorm acondensate, introducing the condensate to a s econd rectifying colunmand subjecting ,the condensate4 to rectification therein vto formasubstantially dry gas and an ultimate `7.4 In the treatmentofhydrocarbon oils,-

ythe process-that comprises conducting -vapors from a pressure' still toa rectifying. column and subjecting the vapors to rectificationthereinwhile still under'a material superatmospheric pressure, removing evolvedvapors from the rectifying column and subjecting a portion of them tocooling to form a condensate, collecting the condensate in a receiverwherein separation of gas and liquid constituents takes place,introducing the liquid from the receiver into a rectifying column andsubjecting the liquid to rectification therein to form a substantiallydry gas and an ultimate condensate while passing the other portion ofthe vapors from the irst rectifying column through a conduit in heatexchange with the ultimate condensate formed in the second re'ctifyingcolumn and discharging the fluids from said conduit into the receiver. ll p 8. In the treatment of hydrocarbon oils, the process that-comprisesconducting vapors from a pressure still to a rectifying column andsubjecting the vapors to rectiication therein while still under amaterial superatmospheric pressure, removing evolved vapors from therec'tifying column and subjecting a portion of them to cooling to form acondensate, collecting the. condensate in a receiver wherein separationof gas and liquid constitutents takes place, introducing the liquid fromthe receiver into a rectifying column and subjecting the liquid torectifikcation therein to form a substantially dry "gas and an ultimatecondensate wliile. assing 65 the other portion of the vaporsfrom t e rstcondensate while passing the other portion rectifying column through aconduit in heat exchange with lthe u timate condensate formed in thesecond rectifying column, conducting the fluid from said conduit toa.cooler 'wherein the liuid is subjected to cooling 70. and dischargingthecooled fluid into the receiver. Y i

9. Inthe treatment of hydrocarbon oils, the process that comprises vconducting f vapors from a pressure still to a rectifying column andsubjecting the vapors'to rectilication thereinJ while still under amaterial superatmospheric pressure, removing evolved vapors from therectifying column and subjecting a portion' of them to cooling to form acondensate, collecting the condensate in a receiver wherein separationof gas and liquid constituents takes place, introducing the liquid fromthe receiver into rectifying column and subjecting the liquid torectiication therein to form a substantially dry gas andan ultimatecondensate while passing the other portion of the vapors fromL the firstrectifying column through a conduit in heat exchange with the ultimatecondensate contained in the second rectifying column, conducting thefluid from `said conj duit to a cooler wherein the fluid is subjectl edto cooling and discharging the cooled fluid into the receiver, removingas a rectified liquid the ultimate condensate collected in the secondrectifying column and taking 0E the substantially dry gas from thereceiver and the second rectifying column.

10. In the treatment of hydrocarbon oils,

the process that comprisesremoving vapors from a pressure still and,while still maintaining them under pressure, effecting a primaryseparation thereof into a liquid and a vapor fraction, passing --vaporsderived from such separation in heat exchange, but not in directcontact, with condensate in the lower part of a rectifying tower tothereby heat said condensate and eect partial condensation of saidvapor, passing the partially con- Vdensed vapor to a cooler to besubjected therein to further coolino and condensation, directing thecooled product into said rectiying tower and\subjecting it torectification therein while cooling the upper part of the tower andwithdrawing theA rectified liquid from the lower part ofthe tower.

In witness whereof I have hereunto set my v hand this 16th day of May,1927.

OTTO BEHIMER.

